PortAudio: paex_sine_c++.cpp Source File

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paex_sine_c++.cpp
1
7 /*
8 * $Id: paex_sine.c 1752 2011-09-08 03:21:55Z philburk $
9 *
10 * This program uses the PortAudio Portable Audio Library.
11 * For more information see: http://www.portaudio.com/
12 * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
13 *
14 * Permission is hereby granted, free of charge, to any person obtaining
15 * a copy of this software and associated documentation files
16 * (the "Software"), to deal in the Software without restriction,
17 * including without limitation the rights to use, copy, modify, merge,
18 * publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so,
20 * subject to the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be
23 * included in all copies or substantial portions of the Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
28 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
29 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
30 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
31 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
32 */
33
34 /*
35 * The text above constitutes the entire PortAudio license; however,
36 * the PortAudio community also makes the following non-binding requests:
37 *
38 * Any person wishing to distribute modifications to the Software is
39 * requested to send the modifications to the original developer so that
40 * they can be incorporated into the canonical version. It is also
41 * requested that these non-binding requests be included along with the
42 * license above.
43 */
44 #include <stdio.h>
45 #include <math.h>
46 #include "portaudio.h"
47
48 #define NUM_SECONDS (5)
49 #define SAMPLE_RATE (44100)
50 #define FRAMES_PER_BUFFER (64)
51
52 #ifndef M_PI
53 #define M_PI (3.14159265)
54 #endif
55
56 #define TABLE_SIZE (200)
57
58 class Sine
59 {
60 public:
61 Sine() : stream(0), left_phase(0), right_phase(0)
62 {
63 /* initialise sinusoidal wavetable */
64 for( int i=0; i<TABLE_SIZE; i++ )
65 {
66 sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
67 }
68
69 sprintf( message, "No Message" );
70 }
71
72 bool open(PaDeviceIndex index)
73 {
74 PaStreamParameters outputParameters;
75
76 outputParameters.device = index;
77 if (outputParameters.device == paNoDevice) {
78 return false;
79 }
80
81 outputParameters.channelCount = 2; /* stereo output */
82 outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */
83 outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
84 outputParameters.hostApiSpecificStreamInfo = NULL;
85
86 PaError err = Pa_OpenStream(
87 &stream,
88 NULL, /* no input */
89 &outputParameters,
90 SAMPLE_RATE,
91 FRAMES_PER_BUFFER,
92 paClipOff, /* we won't output out of range samples so don't bother clipping them */
93 &Sine::paCallback,
94 this /* Using 'this' for userData so we can cast to Sine* in paCallback method */
95 );
96
97 if (err != paNoError)
98 {
99 /* Failed to open stream to device !!! */
100 return false;
101 }
102
103 err = Pa_SetStreamFinishedCallback( stream, &Sine::paStreamFinished );
104
105 if (err != paNoError)
106 {
107 Pa_CloseStream( stream );
108 stream = 0;
109
110 return false;
111 }
112
113 return true;
114 }
115
116 bool close()
117 {
118 if (stream == 0)
119 return false;
120
121 PaError err = Pa_CloseStream( stream );
122 stream = 0;
123
124 return (err == paNoError);
125 }
126
127
128 bool start()
129 {
130 if (stream == 0)
131 return false;
132
133 PaError err = Pa_StartStream( stream );
134
135 return (err == paNoError);
136 }
137
138 bool stop()
139 {
140 if (stream == 0)
141 return false;
142
143 PaError err = Pa_StopStream( stream );
144
145 return (err == paNoError);
146 }
147
148 private:
149 /* The instance callback, where we have access to every method/variable in object of class Sine */
150 int paCallbackMethod(const void *inputBuffer, void *outputBuffer,
151 unsigned long framesPerBuffer,
152 const PaStreamCallbackTimeInfo* timeInfo,
153 PaStreamCallbackFlags statusFlags)
154 {
155 float *out = (float*)outputBuffer;
156 unsigned long i;
157
158 (void) timeInfo; /* Prevent unused variable warnings. */
159 (void) statusFlags;
160 (void) inputBuffer;
161
162 for( i=0; i<framesPerBuffer; i++ )
163 {
164 *out++ = sine[left_phase]; /* left */
165 *out++ = sine[right_phase]; /* right */
166 left_phase += 1;
167 if( left_phase >= TABLE_SIZE ) left_phase -= TABLE_SIZE;
168 right_phase += 3; /* higher pitch so we can distinguish left and right. */
169 if( right_phase >= TABLE_SIZE ) right_phase -= TABLE_SIZE;
170 }
171
172 return paContinue;
173
174 }
175
176 /* This routine will be called by the PortAudio engine when audio is needed.
177 ** It may called at interrupt level on some machines so don't do anything
178 ** that could mess up the system like calling malloc() or free().
179 */
180 static int paCallback( const void *inputBuffer, void *outputBuffer,
181 unsigned long framesPerBuffer,
182 const PaStreamCallbackTimeInfo* timeInfo,
183 PaStreamCallbackFlags statusFlags,
184 void *userData )
185 {
186 /* Here we cast userData to Sine* type so we can call the instance method paCallbackMethod, we can do that since
187 we called Pa_OpenStream with 'this' for userData */
188 return ((Sine*)userData)->paCallbackMethod(inputBuffer, outputBuffer,
189 framesPerBuffer,
190 timeInfo,
191 statusFlags);
192 }
193
194
195 void paStreamFinishedMethod()
196 {
197 printf( "Stream Completed: %s\n", message );
198 }
199
200 /*
201 * This routine is called by portaudio when playback is done.
202 */
203 static void paStreamFinished(void* userData)
204 {
205 return ((Sine*)userData)->paStreamFinishedMethod();
206 }
207
208 PaStream *stream;
209 float sine[TABLE_SIZE];
210 int left_phase;
211 int right_phase;
212 char message[20];
213 };
214
215
216 /*******************************************************************/
217 int main(void);
218 int main(void)
219 {
220 PaError err;
221 Sine sine;
222
223 printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER);
224
225 err = Pa_Initialize();
226 if( err != paNoError ) goto error;
227
228 if (sine.open(Pa_GetDefaultOutputDevice()))
229 {
230 if (sine.start())
231 {
232 printf("Play for %d seconds.\n", NUM_SECONDS );
233 Pa_Sleep( NUM_SECONDS * 1000 );
234
235 sine.stop();
236 }
237
238 sine.close();
239 }
240
241 Pa_Terminate();
242 printf("Test finished.\n");
243
244 return err;
245
246 error:
247 Pa_Terminate();
248 fprintf( stderr, "An error occured while using the portaudio stream\n" );
249 fprintf( stderr, "Error number: %d\n", err );
250 fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
251 return err;
252 }